such changes. In response to this issue, "enabling approaches" to prevention have recently gained attention (Tawil et al., 1995; O'Reilly and Piot, 1996). These interventions are intended to either remove barriers to adoption of protective behaviors or to erect barriers to risky behaviors. An example of how structural or environmental changes can significantly reduce risky sexual behaviors is the "100% Condom Program" that was implemented nationwide in Thailand by the Thai HIV/AIDS Prevention and Control Program in 1992, along with a mass media condom-promotion campaign and wide distribution of condoms to prevent the spread of HIV among sex workers (Rojanapithayakorn and Hanenberg, 1996). The program enforced universal use of condoms among sex workers through the use of sanctions against sex establishments where condoms were not being consistently used. This intervention was effective apparently because it supported desired behavior change and did not reduce the income of sex workers. An extensive evaluation of the program among Thai army male conscripts showed that the proportion of men who had sex with sex workers fell, the proportion who used condoms with sex workers increased, and the seroprevalence of HIV and the proportion with a history of an STD declined significantly after program implementation (Nelson et al., 1996). These data indicate that environmental interventions that adequately address structural or other barriers to behavior change are necessary for the adoption of healthy sexual behaviors.
School is an obvious venue for providing information regarding STDs and for preventing the initiation of high-risk sexual behaviors among adolescents. More than half of teenagers surveyed in 1995 indicated that the school was their primary source of information (ASHA, 1996). As of mid-1994, 45 states and approximately 91 percent of school districts required schools to offer health education (Collins et al., 1995). Five states required a separate course devoted almost entirely to health topics in all elementary schools, 14 required such courses at the middle/junior high school level, and 28 required such courses in senior high school. A 1994 survey of state education agencies and teachers by the CDC showed that 28 of 43 states and the District of Columbia and 81 percent of school districts required teaching STD prevention in a required course (CDC, 1996b). In addition, 39 states plus the District of Columbia required HIV prevention education. As of September 1995, 22 states and the District of Columbia had legal mandates that required schools to provide both sexuality and STD/HIV education; an additional 15 states require schools to provide only STD/HIV education; and 13 states did not require schools to provide sexuality or STD/HIV education (NARAL Foundation, 1995). Many of the states that require education in STD/HIV mention education only for HIV/AIDS, not other STDs, in their laws. Although many states require schools to provide instruction in HIV or STD prevention, these legal mandates are often underfunded and restrictive in the content of